January 11, 2005

Features on the surface of Saturn's moon Rhea reveal clues about the moon's history. In this Cassini image, two large impact basins near center and bottom exhibit central peaks. The image shows largely the trailing hemisphere of Rhea. At right, some of the wispy markings that cover the moon's trailing hemisphere are visible. Rhea's diameter is 1,528 kilometers (949 miles) across. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Dec. 9, 2004, at a distance of 2.5 million kilometers (1.6 million miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 62 degrees. The image scale is about 15 kilometers (9 miles) per pixel. The image has been magnified by a factor of two and contrast enhanced to aid visibility.
Ancient Impacts - (PIC)

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January 11, 2005

This map illustrates the planned imaging coverage for the Descent Imager/Spectral Radiometer, onboard the European Space Agency's Huygens probe during the probe's descent toward Titan's surface on Jan. 14, 2005. The Descent Imager/Spectral Radiometer is one of two NASA instruments on the probe. The colored lines delineate regions that will be imaged at different resolutions as the probe descends. On each map, the site where Huygens is predicted to land is marked with a yellow dot. This area is in a boundary between dark and bright regions. This map was made from the images taken by the Cassini spacecraft cameras on Oct. 26, 2004, at image scales of 4 to 6 kilometers (2.5 to 3.7 miles) per pixel. The images were obtained using a narrow band filter centered at 938 nanometers - a near-infrared wavelength (invisible to the human eye) at which light can penetrate Titan's atmosphere to reach the surface and return through the atmosphere to be detected by the camera. The images have been processed to enhance surface details. Only brightness variations on Titan's surface are seen; the illumination is such that there is no shading due to topographic variations. For about two hours, the probe will fall by parachute from an altitude of 160 kilometers (99 miles) to Titan's surface. During the descent the camera on the probe and five other science instruments will send data about the moon's atmosphere and surface back to the Cassini spacecraft for relay to Earth. The Descent Imager/Spectral Radiometer will take pictures as the probe slowly spins, and some these will be made into panoramic views of Titan's surface. This map (PIA06172) shows the expected coverage by the Descent Imager/Spectral Radiometer side-looking imager and two downward-looking imagers - one providing medium-resolution and the other high-resolution coverage. The planned coverage by the medium- and high-resolution imagers is the subject of the second map (PIA06173).
Go Huygens! - (PIC1) - (PIC2)

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January 11, 2005

Huygens sets off with correct spin and speed
On Christmas Day 2004, the Cassini spacecraft flawlessly released ESA’s Huygens probe, passing another challenging milestone for Cassini-Huygens mission. But, with no telemetry data from Huygens, how do we know the separation went well? At 3:00 CET on 25 December, the critical sequence loaded into the software on board Cassini was executed and, within a few seconds, Huygens was sent on its 20-day trip towards Titan. As data from Cassini confirm, the pyrotechnic devices were fired to release a set of three loaded springs, which gently pushed Huygens away from the mother spacecraft. The probe was expected to be released at a relative velocity of about 0.35 metres per second with a spin rate of about 7.5 revolutions per minute. Telemetry data from Cassini confirming the separation were collected by NASA’s Deep Space Network stations in Madrid, Spain, and Goldstone, California, when the telemetry playback signal from Cassini eventually reached the Earth...

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Huyghens detailed descent timeline can be find here.

Time is in CET.

CET = UTC +1h.

Landing on Liquid?

Summary (Jan 11, 2005): After flying 2 billion miles, a probe to Saturn's moon will attempt what has never been tried before. The Huygens' probe will plunge into Titan and its mysterious atmosphere on Jan. 14, 2005. Whether it will crash or splash has become of extreme scientific interest to those watching the controlled collision.

To Crash or Splash, That is the Question
based on JPL report

Joined at the hip for the last seven years, Cassini and Huygens finally separated Dec. 24 PST after a 3.5 billion kilometer (2.2 billion mile) journey through our solar system. While the Cassini spacecraft continues its four-year tour of the Saturnian system, the Huygens probe will plunge into Titan and its mysterious atmosphere on Jan. 14, 2005. Built and managed by the European Space Agency, Huygens will be the furthest object to touchdown on an alien world. The mission will provide information that may help us better understand Saturn's biggest moon, the only moon in the solar system with a thick atmosphere.
...

read the interesting Story at Astrobiology Magazine Landing on Liquid?

Greetings from Germany NRW
Ulli S@h Berkeley's Staff Friends Club m7 ©

January 10, 2005

Coming Jan. 14 ... Huygens at Titan
Get ready for two of the strangest hours in the history of space exploration. Two hours. That's how long it will take the European Space Agency's Huygens probe to parachute to the surface of Titan on January 14th. Descending through thick orange clouds, Huygens will taste Titan's atmosphere, measure its wind and rain, listen for alien sounds and, when the clouds part, start taking pictures. No one knows what the photos will reveal. Icy mountains? Liquid methane seas? Hot lightning? "It's anyone's guess," says Jonathan Lunine, a professor of planetary science at the University of Arizona and a member of the Huygens science team. "We might not even understand what we see, not immediately." Such is Titan--the biggest mystery in the solar system...

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January 10, 2005

The Cassini visual and infrared mapping spectrometer analyzed the surface composition of Saturn's moon Iapetus as Cassini flew over the polar region on Dec. 31, 2004. The image at left shows the reflectance at 4-microns, which is dominated by the minerals on Iapetus' surface. Two large craters are seen in this image. The polar water ice is relatively dark at this wavelength, so the ice cap is not seen. The next frame shows carbon dioxide on the surface. The carbon dioxide peaks at mid latitudes and shows less strength at the pole and along the equator (the dark band curving near the left edge of the image). The third frame shows the strength of water absorption on Iapetus. The brightest regions are due to water ice near the pole. The grayer areas indicate water bound to minerals on the surface. The color composite shows water as blue, carbon dioxide as green, and non-ice minerals as red.
Iapetus Surface Composition - (PIC)

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January 10, 2005

This color composite image of Saturn's moon Iapetus from Cassini's visual and infrared mapping spectrometer was obtained on Dec. 31, 2004, an hour and a half before the New Year, at a distance of 121,000 kilometers (75,186 miles), with a spatial resolution of about 60 kilometers (37 miles). The three colors used in the mosaic correspond to 1.01, 3.21, and 3.80 microns. The different colors represent vastly different surface compositions. The upper bright blue region is rich in water ice, while the lower, dark brown region is composed mainly of a substance rich in organic material. The yellow region consists of a mixture of ice and organics, suggesting a gradual change in composition on the surface. This pattern suggests Iapetus swept up the dark material, which may have come from debris created from meteoritic impacts onto the small, outer satellites of Saturn.
VIMS Shows Iapetus Surface Composition - (PIC)

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January 10, 2005

Impact-battered Rhea exhibits a mottled appearance in this Cassini spacecraft image. On an ancient surface such as this, large impact basins are often peppered with many smaller craters. The image shows principally the trailing hemisphere of this icy moon, Saturn¿s second largest. Rhea's diameter is 1,528 kilometers (949 miles) across. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Dec. 9, 2004, at a distance of 2.3 million kilometers (1.4 million miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 60 degrees. The image scale is about 14 kilometers (9 miles) per pixel. The image has been magnified by a factor of two and contrast enhanced to aid visibility.
Mottled Rhea - (PIC)

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January 7, 2005

Titan Touchdown - (PIC) - (MOVIE)
Joined at the hip for the last seven years, Cassini and Huygens finally separated Dec. 24 PST after a 3.5 billion kilometer (2.2 billion mile) journey through our solar system. While the Cassini spacecraft continues its four-year tour of the Saturnian system, the Huygens probe will plunge into Titan and its mysterious atmosphere on Jan. 14, 2005. Built and managed by the European Space Agency, Huygens will be the furthest object to touchdown on an alien world. The mission will provide information that may help us better understand Saturn's biggest moon, the only moon in the solar system with a thick atmosphere...

NASA TV/webcast will carry ESA TV during the Titan events.
Check the TV schedule for full details.

ESA Control Room Webcam

Virtual tour of ESA's Spacecraft Operations Center

January 7, 2005

Saturn's Moon Iapetus Shows a Bulging Waistline - (PIC)
Images returned by NASA's Cassini spacecraft cameras during a New Year's Eve flyby of Saturn's moon Iapetus (eye-APP-eh- tuss) show startling surface features that are fueling heated scientific discussions about their origin. One of these features is a long narrow ridge that lies almost exactly on the equator of Iapetus, bisects its entire dark hemisphere and reaches 20 kilometers high (12 miles). It extends over 1,300 kilometers (808 miles) from side to side, along its midsection. No other moon in the solar system has such a striking geological feature. In places, the ridge is comprised of mountains. In height, they rival Olympus Mons on Mars, approximately three times the height of Mt. Everest, which is surprising for such a small body as Iapetus. Mars is nearly five times the size of Iapetus...

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January 7, 2005

This stereo view of Iapetus was created by combining two Cassini images, which were taken one day apart. The view serves mainly to show the spherical shape of Iapetus and some of the moon's topography. The prominent linear ridge in the center of the dark area -- a place known as Cassini Regio -- marks the equator quite closely. The ridge was first discovered in this set of images and was seen at higher resolution in images taken during Cassini's flyby of Iapetus on New Year's Eve 2004. Some Cassini imaging scientists have suggested that the ridge may have a causal relationship to the dark material that coats the moon's leading hemisphere. The mountain on the left is part of the ridge, and rises at least 13 kilometers (8 miles) above the surrounding terrain. The large basin near the terminator (at upper right) was detected in Cassini images from July and has a diameter of about 550 kilometers (340 miles). The large basin at upper left was newly detected in these images. The crater at far right (within the bright terrain) was known from the days of NASA's Voyager missions. North on Iapetus is towards the upper left. The images were obtained in visible light with the Cassini spacecraft narrow angle camera on Dec. 26 and 27, 2004. Cassini's distance from Iapetus ranged from 880,537 to 716,678 kilometers (547,140 to 445,323 miles) between the two images, and the Sun-Iapetus-spacecraft, or phase, angle changed from 21 to 22 degrees. Resolution achieved in the original images was 5.2 and 4.3 kilometers (3.2 and 2.7 miles) per pixel, respectively.
Iapetus in 3D - (PIC)

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January 7, 2005

Wave-like patterns in Saturn's rings and a nearly half-full Mimas are caught together in this image from Cassini. Mimas is 398 kilometers (247 miles) across. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Nov. 19, 2004, at a distance of approximately 4.8 million kilometers (3 million miles) from Saturn. The image scale is 29 kilometers (18 miles) per pixel.
Saturn's Ring Patterns - (PIC)

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January 6, 2005

The sunlight angle in this sharp view of Saturn's second-largest moon, Rhea, highlights the moon's crater-strewn surface. Cassini will fly past Rhea on Nov. 26, 2005, at a distance of only 500 kilometers (311 miles) and will obtain very high resolution images at that time. Rhea's diameter is 1,528 kilometers (949 miles). This view shows mainly the hemisphere of Rhea that faces away from Saturn. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Nov. 1, 2004, at a distance of 1.6 million kilometers (994,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 102 degrees. North is up. The image scale is about 10 kilometers (6 miles) per pixel. The image has been slightly contrast enhanced to aid visibility of surface features.
Rhea's Ancient Surface - (PIC)

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January 5, 2005

This Cassini image captured Saturn's moon Pan (25 kilometers, or 16 miles, across) just after the little moon emerged from Saturn's shadow. Pan orbits within the narrow Encke Gap (300 kilometers, or 186 miles, wide). A faint hint of the narrow ringlet within the Encke Gap in earlier Cassini images (see PIA06534) is visible here. Saturn's rings appear extremely overexposed due to the enhancement used to make Pan visible, but the processing technique also makes other faint features stand out. In addition to the bright, knotted core of the F ring, two faint nearby ringlets can be seen. At right, this view of the Cassini Division shows that there is actually a great amount of material embedded within it. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Dec. 1, 2004, at a distance of approximately 4.1 million kilometers (2.5 million miles) from Saturn. The image scale is 25 kilometers (15 miles) per pixel.
Faint Ring Details - (PIC)

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VideoTalk: Clues to how life began

look at this very interesting Video

VideoTalk: Clues to how life began

Greetings from Germany NRW
Ulli S@h Berkeley's Staff Friends Club m7 ©

January 4, 2005

Rhea has been heavily bombarded by impacts during its history. In this Cassini image the moon displays what may be a relatively fresh, bright, rayed crater near Rhea's eastern limb. Rhea is 1,528 kilometers (949 miles) across. This view is centered on the side of Rhea that faces away from Saturn as the moon orbits. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Nov. 10, 2004, at a distance of 3.6 million kilometers (2.2 million miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 86 degrees. North is up. The image scale is 21 kilometers (13 miles) per pixel. The image has been magnified by a factor of two and contrast enhanced to aid visibility of surface features.
Fresh Crater? - (PIC)

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January 3, 2005

From beneath the ring plane, the small, irregularly shaped moon Janus (181 kilometers, or 112 miles, across) can be seen following the orbital path it shares with slightly smaller Epimetheus (116 kilometers, or 72 miles, across). The image was taken in visible red light with the Cassini spacecraft narrow angle camera on Nov. 18, 2004, at a distance of approximately 4.7 million kilometers (2.9 million miles) from Saturn. The image scale is 27 kilometers (17 miles) per pixel.
Janus and Rings - (PIC)

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New Years Day

This image of Iapetus was taken on Dec. 31, 2004 at a range of about 71,978 kilometers (44,725 miles) from the icy moon. This image has not been validated or calibrated. Iapetus is Saturn's two-faced moon -- one side is very bright, and the other is very dark. One scenario for this striking difference is that the moon's surface is being resurfaced by some material spewing from within.
(PIC) - (MOVIE)

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December 31, 2004

Cassini spied a crater-covered Dione in this image from Dec. 8, 2004. The bright, wispy streaks for which Dione is known are located on the moon's night side to the west. The streaky terrain was imaged at very high resolution by Cassini during its flyby of Dione on Dec. 14, 2004. Dione is 1,118 kilometers (695 miles) across. This view shows mostly the trailing hemisphere of Dione. The image was taken in visible light with the Cassini spacecraft narrow angle camera at a distance of 2.5 million kilometers (1.6 million miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 58 degrees. North is up. The image scale is 15 kilometers (9 miles) per pixel. The image has been magnified by a factor of two and contrast-enhanced to aid visibility of surface features.
Pocked Moon - (PIC)

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